[cairo-commit] src/cairo-scaled-font.c

[Adrian Johnson]

 src/cairo-scaled-font.c |    7 +++++++
 1 file changed, 7 insertions(+)

New commits:
commit 5fd0b8710f125bb33c55d75fcc8252996b403e2d
Author: Carlos Garcia Campos <cgarcia at igalia.com>
Date:   Wed Oct 18 11:33:25 2017 +0200

    scaled-font: Fix assert when destroying glyph page
    
    This happens when _cairo_ft_scaled_glyph_init() returns
    CAIRO_INT_STATUS_UNSUPPORTED when called from
    _cairo_scaled_glyph_lookup(). In those cases
    _cairo_scaled_font_free_last_glyph() is called to release the glyph that
    has just been allocated. If there aren't more glyphs,
    _cairo_scaled_glyph_page_destroy() is called. The problem is that
    _cairo_scaled_glyph_lookup() should always be called with the cache
    frozen, and _cairo_scaled_glyph_page_destroy() without the cache
    frozen. We can simply thaw/freeze the font before calling
    _cairo_scaled_glyph_page_destroy().
    
    https://bugs.freedesktop.org/show_bug.cgi?id=103335

diff --git a/src/cairo-scaled-font.c b/src/cairo-scaled-font.c
index 705e55bd..45885702 100644
--- a/src/cairo-scaled-font.c
+++ b/src/cairo-scaled-font.c
@@ -2923,6 +2923,7 @@ _cairo_scaled_font_free_last_glyph (cairo_scaled_font_t *scaled_font,
 {
     cairo_scaled_glyph_page_t *page;
 
+    assert (scaled_font->cache_frozen);
     assert (! cairo_list_is_empty (&scaled_font->glyph_pages));
     page = cairo_list_last_entry (&scaled_font->glyph_pages,
                                   cairo_scaled_glyph_page_t,
@@ -2932,6 +2933,9 @@ _cairo_scaled_font_free_last_glyph (cairo_scaled_font_t *scaled_font,
     _cairo_scaled_glyph_fini (scaled_font, scaled_glyph);
 
     if (--page->num_glyphs == 0) {
+	_cairo_scaled_font_thaw_cache (scaled_font);
+	CAIRO_MUTEX_LOCK (scaled_font->mutex);
+
 	CAIRO_MUTEX_LOCK (_cairo_scaled_glyph_page_cache_mutex);
 	/* Temporarily disconnect callback to avoid recursive locking */
 	cairo_scaled_glyph_page_cache.entry_destroy = NULL;
@@ -2940,6 +2944,9 @@ _cairo_scaled_font_free_last_glyph (cairo_scaled_font_t *scaled_font,
 	_cairo_scaled_glyph_page_destroy (scaled_font, page);
 	cairo_scaled_glyph_page_cache.entry_destroy = _cairo_scaled_glyph_page_pluck;
 	CAIRO_MUTEX_UNLOCK (_cairo_scaled_glyph_page_cache_mutex);
+
+	CAIRO_MUTEX_UNLOCK (scaled_font->mutex);
+	_cairo_scaled_font_freeze_cache (scaled_font);
     }
 }